Explanation
Use the present perfect for a very recent event when the result matters now.
For example, "I have just eaten lunch." Here, "I" is the subject, "have eaten" is the present perfect, and "just" means the action happened very recently. We do not say the exact time, so the sentence feels close to the present. Japanese often says "さっき" or "もう" with a past idea, but English often uses "have/has + past participle" for this meaning. If you want to name the exact time, use the past simple instead, like "I ate lunch at 12:30."
今の結果が大事な、つい最近の出来事を言うときに現在完了を使います。
例えば、"I have just eaten lunch." では、"I" が主語、"have eaten" が現在完了、"just" が「たった今、少し前」を表します。具体的な時刻は言わないので、今にとても近い感じになります。日本語では「さっき」「もう」を過去の表現と一緒に言うことが多いですが、英語ではこの意味で "have/has + 過去分詞" を使います。時刻をはっきり言いたいなら、"I ate lunch at 12:30." のように過去形にします。
Examples
- I have just eaten lunch. ちょうど昼ごはんを食べたところです。
- She has already left. 彼女はもう出かけました。
- Have you finished your report yet? レポートはもう終わりましたか。
- We have not started the meeting yet. まだ会議を始めていません。
- The bus has just arrived. バスがちょうど到着しました。
- I have already sent the email. メールはもう送りました。
Common Mistakes
Japanese learners often add an exact past time to the present perfect.
Wrong: "I have just finished my homework at 8."
Right: "I finished my homework at 8."
If you use the present perfect, keep the time general, like "I have just finished my homework."
日本語話者は、現在完了に具体的な時刻を足してしまいがちです。
誤り: "I have just finished my homework at 8."
正しくは: "I finished my homework at 8."
現在完了を使うなら、"I have just finished my homework." のように時刻をぼかします。